The snowshoer’s hands were bigger than mine. Considering how small Mr. Barlow was, his hands always looked large to me. Suddenly his hands were locked at the businessman’s waist, the knuckle of one thumb pressed into the guy’s navel. The businessman was clawing at Mr. Barlow’s locked hands, but there were no loose fingers to peel apart. When Elliot locked his hands, he knew how to tuck his thumbs and fingers away; there was nothing to grab. The snowshoer’s locked hands were a double knot.

I just waited for the back-heel trip; Mr. Barlow had a good one. I knew it was coming. The business guy had no idea what was coming. His left cheek was what made a slapping sound against the pavement of the station platform. The little snowshoer had to step over the guy to board the train; Mr. Barlow brought the second of my two backpacks aboard with him.

We took a long time stowing my bags. When the train began to move, we had just sat down. The business guy was still on the station platform, but I was relieved to see he was sitting up of his own accord. The two people attending to him were not holding him up, and the businessman had a reasonably alert expression on his face. The way the guy just talked and talked made me wish I could have heard his account of what happened to him.

“ ‘There was this midget fairy—he managed to get behind me, somehow,’ ” I said to the snowshoer, as if that were the whole story.

“ ‘There were four of them—two of them held me, while the other two picked up the station platform and hit me in the face with it,’ ” Mr. Barlow began his version of the story.

“ ‘Four huge guys—all of them were communists,’ ” I told the little English teacher, who began to laugh.

We were both laughing when the train pulled out of Penn Station, but I didn’t really feel like laughing. I felt afraid. I knew I wasn’t cut out to be a good shepherd. I was wishing I’d told Zim about Mr. Barlow. Matthew Zimmermann had been a hero. Maybe Zim would have known how to save the snowshoer.

ACT III RULES FOR GHOSTS

30. THE WOMAN WITH THE BABY CARRIAGE

There are certain scenes from films you wish you never saw: in your mind, you keep replaying these scenes—or I do. Like those songs that get into your head, the ones you hate but you can’t stop singing.

Like most screenwriters, I keep rewriting my movies that were never made. I won’t presume to speak for other screenwriters, but I also keep rewriting certain scenes I didn’t write in the first place—even scenes from films I wish I never saw.